Hello,
I have an HTML table with several rows. I want to change the row color when the user clicks it. This is quite simple to do with plain javascript, but I want to use rails. Is there any helper or something that performs this task for me?
Thanks for your time.
You realize this is a client-side interaction, which means Javascript
no matter how it's packaged? 
It’s not wrong, it just looks ugly and can be very verbose if you put it on every single row, so a more generic approach is preferrable to say the least.
You have a couple of options:
Either go completely event delegated, mixing in a library specifically designed for this like NWEvents can greatly benefit your application, we use it for everything in our apps and has greatly improved performance, works seamlessly even when replacing or adding new parts to the page that have to exhibit similar behavior and reduced code clutter. It’s a bit like jQuery’s live function, and it supports non bubbling events too, like focus and blur on form elements and form submission
Or you can put the click event observer on the table itself. If you add new tables that need highlighting via ajax, you’ll have to attach a new observer to that one too, as well as clean up observers before destroying elements on the page.
In both cases, inspect the event.target (what element was actually clicked), then go .up(‘tr’) and put the highlight class on the row. If that needs to be saved in the model, just fire an Ajax.Request from your javascript highlight method.
The simple fact of the matter is that you’ll have to write custom javascript and not rely on Rails’ built-in helpers to get a performant and clean solution.
Best regards
Peter De Berdt
You might try leveraging the scriptaculous visual effects library for this: